Carburetor



April 21,1925. 1,534,808

H. G. RENNER CARBURETOR Filed March 18, 1922 briefly', the

Patented Apr.. 21, `1925.

PATENTwoFFlcE.

' .'IAnoLD G. annuali, or DETROIT, MCHIGAN.

CARBURETOR.

\ appncannmea umn 18,3322. serial no. 544,765.

To all fic/wm z'tmoj/ concern: t

Be it known that I, HAROLD-G RliNNjsR; a subject of the King of Great"Britain, re sidin at Detroit, in the county of ;W ayne ATand usefulGarburetor, of which the following is a specification: y

This inven len relates-to,carburetors for internal 'combustion engines,and particularly to the fuel 'feed control of such 'carburetors v Theinvention has for its object the prof, vision of means for effecting atemporary 1ncrease in the quantity of fuel delivered to the carburetorsimultaneously with the open ing' of the throttle to accelerate theengine, and to.,automatically clfect the cutting off of such "increasewithin a predetermined time intervalxof action independently of a returnenclosing/movement of saidthrottl. The inventi iis especially designedand adapted for a lcation to carburetors ofthe type-disclose 1n. mypatent iwssuedSept. 12, 1922, No 1,428,558.` L,

The present- .invention contemplates, employment in'. connection withmeans controlled b the throttle. ,for adjustin a primary uel valve intheoutlet of a nel nozzle,'of a reciprocal piston .operativein'the mannerof'a dash-pot in the fuel chamber ofsaid nozzlejand having` a valve stemnormally seated in and closlng a secondary fuel outlet formed throughsaid primary valve, said pistonbeing urged by a spring toward saidprimary valve ivn the 'opening direction thereof, but, being restrainedagainst following said valve under abrupt or/rapid movement thereof insuch direction, by the retarding action of the liquid, fuel displaced bymovementof said piston vunder influence of said spring, hence a suddenopening movement of the 'primary valve willicause a momentary/or timelimited opening of the secondary fuel inenting the primary jet 1n suppying fuel.

' The duration of actidn of the secondary fuel ondary valve .stem to itsseat in the needle supply will be determined by the speed of travelv ofthe piston in advancing the secvalve and this will bev governed b theclearance provided for the passage o the liquid fuel around the piston.

A preferred embodiment of the invention is hereinafter described andillustrated in the accompanying drawing, wherein,

,i y invention. nd tate oMichigan, have invented afnew Y buretor and 2the air -1`n-let thereof "Fig. 1 is a vertical section longitudinallyintersecting the mixing chamber and its air inlet of a carburetorembodying the present QF ig. 2 is an enlarged cross section on line 2-2of Fig 1, showinga partially opened position, of the automatic air andfuel valves. In these views the reference, character 1 designates themixin `ehanber'of the car- 'the same together forming `a"continuoushorizontal passage. A'lap valve 3 ispivoted upon a pin 4 in the upper.`portion of said passage, and under idling conditions extends diagoi'allyacross the'fpassage in the direction of the low \therethrough," as shownin full lines in Fig. 1.- The relatively small current of air which isdelivered to the mixing chamber under idling kcondi-tions does not exertsufficient pressure Nupon said valve to overcome the weight thereof.kWhen, however, the throttle is adjusted to permit an increased flow, aswhen the engine is under load, the resultant air pressure rocks thevalveiB upwardly through angle prolportionate to the increase of flow..Itis preferred toform. the top of the carburetor casing with an, upwardextension or domex, which will'aceommodate the valve 3 in its positionof'maxix'num eleva-tion. The cen tral portion 6- of. the"v valve formsan arch extending v with ,gradually increasin height from. the pivotalextremity to the free end y chamber 7 is formed in an inte'gral,extension 7. of the carburetor casing beneath the same' and inclined ataslight angle from. the `vertical in the direction 'of flow through themixingchamber. A piston 8 is mounted in said dash-pot chamber and isupwardly `urged by a coiled spring 9 seatl'ed in a cap 9 closing the endof said cham# bered extension, `said piston 'havingI a guide ange10`spz'iced from the head 11 thereof, the latter having a slightclearance fromthe wall of thechamber 7, and the former having apertures12 forthe passage of li uid past said piston'. Liquid fuel is admitte tothe chamber 7 at a point between the piston extremities 10 and 11throughl a port 13 openincr from a 4passage 1,4 leading from a float camber 15 or other suitable source of suppl A'ball check v'alve 15seats-,centrally withn'the piston 8, closing a' ley-pass 15b throughthe-head 11 when thepiston is Cil rising but lifting therefrom upondownward movement of the piston to permit the liquid below the head 11to flow freely vthrough said b v-pass and thus relieve the piston fromthc resistance such as is set up by the displacement of the liquidthrough the clearance around the piston head as occurs in the risingmovement thereof.

A passage 16 primarily providing for a delivery of liquid fuel from thechamber .7 to the mixing chamber, opens into the latter beneath the freeend of the air valve 3. Said passage iscontrolled by a primary fuelvalve 17, which is formed with a secondary fuel feed passage 18,therethrough under control of a valve formed by the rounded upper end ofa stem 19, integrally rising from the piston 8. The valve 17 is carriedby the free end of a rockearm, comprising a strip of sheet metal 2Oextending through the arch of the valve 3 and a leaf .spring 21 securedto the other end of said strip and attached by a screw 22 to the topface of the air inlet adjacent the mouth thereof. The connection betweensaid spring and strip may be established by brazing, soldering, or inany other suitable manner. Said spring is stressed toiurge the rock-arm2O upwardly, but not with sufficient force to overcome the weight of thevalve 3, which acts upon the rock-arm through a block 23 apertured toengage the rock-arm and having its top rounded to bear upon a plate 24:carried by said valve. The block 23 is adjustable longitudinally of therock-arm 2O by means of a bar 24, arranged beneath said strip andsecured at one end to said block. The other end portion of said barforms a rack 25engaged by a pinion 26 fast upon a shaft 27 adjacent thespring 21. Said shaft mayfhave an end portion (not shown) projectingexteriorly of the carburetor casing and rotatively act-uable by anysuitable means. At 2S is indicated the usual throttle member controllingthe outlet from the mixing chamber.

Considering now the operation of the described farburetor, it is to beunderstood that under idling conditions the valve 3 rests upon the floorof the passage 1, 2, and that the primary fuel valve 17 remains slightlyraised from its seat allowing a flow of air and fuel through thecomparatively restricted passage formed by the arch member G. When thethrottle 28 is opened more or less, there is a corresponding increase inthe flow of air into the mixing chamber, and under such conditions, thevalve 3 is rocked upwardly by the pressure of air, as for eX- ample, tothe position indicated in dash lines in Fig. 1. Such movement of thevalve 3 permits the rock-arm 20-21 to likewise,

swing upwardly responsive to the effort of` the spring 21, andconsequently the primary fuel valve 17 is withdrawn from the fuelpassage 1G to an extent determined b v the angle through which the valve3 and said rock-arm have been shifted. Under the up! ward effort exertedby the springn) upon the piston S and valve 19, the latter tends tofollow the primary valve 17 as the latter is raised from its seat, butowing to the retarding effect of the dash-pot the valve 19 is restrainedfrom immediately following the primary valve when the opening movementof the latter is abrupt or rapid. Consequently, under such conditionsthe seeondary fuel passage 18 is opened and the mixture is enriched bythe supplementary delivery of fuel through said passage. lf, however,the opening movement of the primary fuel valve is gradual the retardingeffect of the dash-pot will not be sufficient to prevent the secondaryvalve immediately following the primary valve in the opening movement ofthe latter, thus preventing opening of the secondary fuel passage andthe issuance of fuel therfrom.

It will be noted that the functioning of the secondary fuel valve is notdependent upon the specific means disclosed for operatin the primaryfuel valve, but that said secon ary valve will readily function asdescribed in connection with an apertured fuel valve actuated by anysuitable means.

What I claim is:

1. A carburetor comprising a mixing chamber, a valve controlling aprimary fuel supplywto said chamber,r said valve having a passage for asecondary fuel supply, a secondary valve normally seating upon theprimary control valve to close said passage, means urging said secondaryvalve to its seat, tending to maintain said passage closed during theopening movement of the primary val-ve, and means retarding the movement of the secondary valve in the direction of'opening of the primaryvalve.

2. A carburetor comprising a mixing chamber, a valve controlling aprimary liquid'fuel inlet to said chamber, said valve being formed witha secondary fuel inlet `substantially co-axial with the primary inlet, asecondary valve normally seating upon the primary valve toclose saidinlet there- 115 in, a spring normally ,urging said secondary valve toits seat, tending to maintain the seeondary inlet closed during openingof the primary valve, and means retarding the increment of the secondaryvalve in the direction of opening of the primary valve.

3. A carburetor, comprising a mixing chamber, 'a valve controlling aprimary liquid fuel inlet to said chamber, said valve being formed witha secondary liquid fuel inlet, a follower valve seating upon. the'irstmentioned valve oppositely to the direction of seat-ing of the latterand controlling said secondary fuel inlet, a spring urging said followervalve to its seat in the direction 13o of opening of the primary valve,and 'a dash. 5. In a carburetor, e casing having e, miie 20 potretarding the seating movement of said follower valve.

el. A carburetor, comprising a' mixing chamber, a valve controlling eprimary liquid fuel inlet to said chamber, said valve beingforined withe 'secondary liquid fuel inlet, u follower vulve seating upon the firstmentioned vvalue oppositely to the direction. of seating of the latterund controlling said secondary inlet, e 'piston connected Ato saidfollower ,\f'ulve, a' liquid fuel chamber in which Suid 'piston operatesas a dash pot to retard seating of the follower valve, Suid chambercommunicating with said primary ing chamber, and formed with un airinlet and' e primary liquid fuelinlet to seid chunk lier, e valvecontrolling said air inlet respon sive to air pressure, a primary valvecontrolling said liquid fuel inlet, and urged to its seat by said airvalve in closed position of the latter, said primary valve being formedwith a secondary fuel inlet, a seo ondary fuel valve seating upon theprimary valve in the direction of opening tloereoil und controlling saidsecondary inlet, Ineensurging said secondary valve to follow the primaryvalve when the latter is unseated, and means 'for rtarding suchfollowing movement of the secondary valve.

In testimony whereof I sign this specification.

HAROLD G. RENNER.

